They responded to the call of Allaah The Almighty immediately after they disobeyed Him when Shaytaan (Satan) caused them to slip and drove them to commit a sin. They hastened to show remorse and to repent. Allaah The Almighty Says (what means): {They said, "Our Lord, we have wronged ourselves, and if You do not forgive us and have mercy upon us, we will surely be among the losers.} [Quran 7:23]

Nooh (Noah) :

When he felt sympathy for his disbelieving son, he said (what means): {…"My Lord, indeed my son is of my family; and indeed, Your promise is true; and You Are the most just of judges!} [Quran 11:45] Then Allaah The Almighty Said to him (what means): {…"O Nooh, indeed he is not of your family; indeed, he is [one whose] work was other than righteous, so ask Me not for that about which you have no knowledge. Indeed, I advise you, lest you be among the ignorant.} [Quran 11:46]

Then, Nooh asked for the forgiveness of Allaah The Almighty, repenting of what he said. Allaah The Almighty Says (what means): {… "My Lord, I seek refuge in You from asking that of which I have no knowledge. And unless You forgive me and have mercy upon me, I will be among the losers.} [Quran 11:47]

Besides, after Allaah The Exalted had punished the disbelieving people of Nooh with drowning and saved the believing people with Nooh he said(which means): {My Lord, forgive me and my parents and whoever enters my house a believer and the believing men and believing women. And do not increase the wrongdoers except in destruction.} [Quran 71:28]

Ibraaheem (Abraham) :

Ibraaheem who was the intimate friend of Allaah The Exalted, said in the verse (which means): {And who I aspire that He will forgive me my sin on the Day of Recompense.} [Quran 26:82]

Moosa (Moses) :

Moosa says in the verse (which means): {He said, “My Lord, indeed I have wronged myself, so forgive me,” and He forgave him. Indeed, He is the Forgiving, the Merciful.} [Quran 28:16] He also says (what means): {[Moosa] said, "My Lord, forgive me and my brother and admit us into Your mercy, for You are the Most Merciful of the merciful.} [Quran 7:151]

Muhammad :

The Companions of the Prophet narrated that the Prophet used to seek the forgiveness of Allaah The Almighty at least one hundred times in each gathering, saying: "O Lord, forgive my sins and grant me (accept my) repentance; for You are the Accepting of repentance, the Merciful." In another version: "… You are the Forgiving, the Merciful." [Abu Daawood] The Prophet said: "By Allaah! I ask for forgiveness from Allaah The Exalted and turn to Him in repentance more than seventy times a day." [Al-Bukhaari]

Furthermore, Allaah The Almighty urges the Prophet to seek His forgiveness. He, the Exalted, Says (what means): {… ask forgiveness for your sin and for the believing men and believing women…} [Quran 47:19]

Yoonus (Jonah) :

Prophet Yoonus called out in the darkness of the whale’s belly (what means): {There is no deity except You; exalted are You. Indeed, I have been of the wrongdoers.} [Quran 21:87]

Daawood (David) :

Daawood supplicated Allaah The Exalted as Allaah The Exalted Says (what means): {And Daawood became certain that We had tried him, and he asked forgiveness of his Lord and fell down bowing [in prostration] and turned in repentance [to Allaah].} [Quran 38: 24]

Abu Bakr :

Abu Bakr the best of this nation after the Prophet asked the Prophet "O Messenger of Allaah, teach me an invocation with which I may invoke Allaah in my prayers.” The Prophet said: “Say, ‘Allaahumma inni thalamtu nafsi thulman katheeran wa la yaghfir ath-thunoob illa ant; ighfir li maghfiratan min ‘indik wa irhamni, innaka anta Al-Ghafoor Ar-Raheem (O Allaah, I have wronged my soul very much and none forgives the sins but You; so please bestow Your forgiveness and mercy upon me. No doubt, You are the Oft-Forgiving, the Most Merciful).’” [Al-Bukhaari]

‘Umar :

‘Umar said to the Prophet "O Messenger of Allaah, ask forgiveness for me."

There are numerous righteous and devout people other than these, who used to seek the forgiveness of Allaah The Almighty frequently; repentance was their banner, their request for forgiveness was their slogan, and they repeatedly turned to Allaah The Almighty.